Suture techniques and patch materials using an in-vitro model for watertight closure of in-utero spina bifida repair

J Pediatr Surg. 2020 Apr;55(4):726-731. doi: 10.1016/j.jpedsurg.2019.05.024. Epub 2019 Jun 19.

Abstract

Purpose: Despite proven benefits of in-utero spina bifida (SB) repair, ≥30% of children at birth have Chiari II malformation or cerebrospinal fluid (CSF) leakage from the repair site. Our study's purpose was to determine CSF pressures in the myelomeningocele sac during mid-gestation in order to design an in-vitro model for evaluating different surgical methods used for watertight closure during in-utero SB repair.

Methods: CSF pressures were measured during in-utero SB repair at mid-gestation. An in-vitro chicken thigh model, simulating fetal tissue, tested watertight closure when attached to the base of a water column. Primary closure methods were evaluated using defect sizes of 20 × 3 mm for minimal traction or 20 × 8 mm for moderate traction. Additionally, 3 common in-utero repair patches were compared using 15 × 15 mm defects.

Results: Using 6-12.5 cm pre-determined CSF pressures, 165 in-vitro experiments were performed. Regardless of methodology we found that in 66 primary-based closures that minimal versus moderate wound edge traction provided better seals. The locking method was superior to the non-locking technique for watertight closure in 99 patch-based closures.

Conclusions: Minimal wound edge traction was best for primary closures, and locking sutures ideal for patch-based closures, however surgical techniques should be individualized to improve upon clinical outcomes.

Keywords: Hindbrain herniation reversal; Myelomeningocele; Spina bifida; Surgical techniques; Watertight closure.

MeSH terms

  • Animals
  • Chickens
  • Female
  • Fetal Therapies* / instrumentation
  • Fetal Therapies* / methods
  • Humans
  • In Vitro Techniques
  • Neurosurgical Procedures* / instrumentation
  • Neurosurgical Procedures* / methods
  • Pregnancy
  • Spinal Dysraphism* / surgery
  • Suture Techniques*
  • Thigh
  • Traction